Isolation, purification and identification of polysaccharides from cultured Cordyceps militaris

Four polysaccharides from the water extract of cultured Cordyceps militaris were isolated through ethanol precipitation, deproteination and gel-filtration chromatography. Their molecular weights were determined using gel-filtration chromatography. Among the four isolated polysaccharides, the structures of two of them (CPS-2 and CPS-3) were elucidated by sugar analysis, Smith degradation, IR and (13)C-NMR spectroscopy.     

烘炉温度检测技术的发展

介绍了国内外烘炉温度追踪检测方面技术的发展情况,对传统的温度追踪检测技术进行了分析,针对现存各种测温方法的缺点提出改进方案,并简单介绍了基于MAX6675的烘炉温度追踪仪的研究和设计。     

瓜叶菊耐热无性系Z1-1-1的离体筛选与初步鉴定

以瓜叶菊增殖期的愈伤组织和丛生芽为材料,用高温胁迫和羟脯氨酸 (HYP)分别作为直接和间接选择压,进行瓜叶菊耐热无性系的离体筛选.结果表明:1) 40℃ 16～20h胁迫处理可以作为瓜叶菊耐热无性系离体直接筛选的适宜选择压,30 mmol·L-1 HYP 可以作为瓜叶菊耐热无性系离体间接筛选的适宜浓度;2) 经过高温间隔胁迫多代筛选获得了与其母株相比耐热性有了很大提高的无性系Z1-1-1;3) Z1-1-1 和其对照母株Z1的30 d移栽苗在叶片厚度、气孔指数、栅栏组织厚度/海绵组织厚度方面存在显著差异,另外,成年植株Z1-1-1 和Z1在花的育性上差异明显,Z1结实率85%以上,而Z1-1-1的结实率在人工授粉的情况下也仅1.0%;4) 在40℃ 24h胁迫后,Z1-1-1的热害指数、细胞丙二醛(MDA)含量、电解质伤害性外漏率远远低于其对照母株,而POD、SOD活性明显高于其对照母株,存在显著性差异.     

封杀“入侵者”——国家林业局通报最新外来有害物种防止情况

10月24日，国家林业局召开新闻发布会通报最新外来入侵有害物种刺桐姬小蜂疫情在我国深圳、海南、福建等地发生及防治情况。据国家林业局植树造林司司长魏殿生介绍，刺桐姬小蜂属植食性昆虫，繁殖能力强，生活周期短，1个世代大约1个月左右，1年可发生多代，是2004年定名的新种害虫，主要分布在毛里求斯、夏威夷等地，在我国大陆是新记录。     

简易装卸设备

本文介绍如何拆下集材拖拉机搭载板，安装架杆，利用绞盘机、钢索及架杆滑轮装卸货物。此装卸设备对缓解当前伐区众多分散小型山楞原木装车的困难局面，具有实际指导意义。     

自然保护区生态旅游总体规划理念的探讨

自然保护区生态旅游总体规划是在自然保护区总体规划基础上的专项规划。论述了自然保护区开展生态旅游的基本特征、自然保护区旅游总体规划应遵循的原则,探讨了规划的理论依据,提出了规划应注意的问题。     

The pH change in rhizosphere ofPinus koraiensis seedlings as affected by different nitrogen sources and its effect on phosphorus availability

Root mat method described by Kuchenbuch and Jungk was used to study the rhizosphere processes. The experiment was carried out on two years oldPinus koraiensis seedlings. Soil samples collected from the upper 20-cm soil layer in Changbai Mountain were treated with three different forms of nitrogen fertilizers: NO₃ ⁻−N, NH₄ ⁺−N and NH₄NO₃. The results showed that the soil pH and available P near the roots were all lower than in the bulk soil in control treatment. NH₄ ⁺−N application greatly decreased the soil pH near the roots compared to the control treatment and promoted the absorption of phosphorus, which led to a more remarkable depletion region of available P. On the contrary, the rhizosphere soil pH was higher than in the bulk soil in treatments with NO₃ ⁻−N and retarded the P absorption, which led to a nearly equal available P contents to the bulk soil. In treatment with NH₄NO₃, the rhizosphere soil pH was only a little lower than that in the control treatment and its effects on P absorption is mediate between the treatments with NH₄ ⁺−N and NO₃ ⁻−N. Foundation item: This paper was supported by National Natural Science Foundation of China (Grant No. 30170167). Biography: Chen Yong-liang (1969-), male, Ph. Doctor, lecture of Northeast Forestry University, Harbin 150040, Post-doctor in Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P.R. China. E-mail: ylchin@sohu.com Responsible editor: Seng Funan     

Relationships of climate change and tree ring of Betula ermanii tree line forest in Changbai Mountain

Based on the tree-ring growth characteristics of Erman＇s birch （Betula ermanii charm.） and the relationships between it and climatic ）＇actors at elevation of 1950m, the sensitivity of tree lines in Changbai Mountain to climatic factors was assessed. The results indicated tree line forest in Changbai Mountain had an obvious sensitivity to climate factors. However, difference from other study sits is that the main climatic control factor on tree-ring growth was not current growth season temperatures, as might be expected, but previous winter and current March temperature. Although the precipitation in the region was quite abundant, the tree-ring growth was still significantly correlated with the precipitation during previous winter and current spring. Additionally, climatic factors which influenced the Erman＇s birch growth were not the yearly variables, but seasonal and monthly variables. Therefore, the reported increase in yearly mean temperature and total yearly precipitation since 1980s was not responded by sustained increase in ring widths in recent decades.     

浑善达克沙地复合式固沙造林技术分析

复合式造林技术 ,实施后形成带、网、片 ,乔、灌 ,针、阔混交复合式格局 ,变一般固沙型式所形成的单一脆弱植物结构 ,为多样性生物群落 ,使防沙治沙效益向更高层次发展。